SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc5fdf1411df9dc3a78c038bd9e8cc0218546198023a71ed3a4dd53b48095a3' 
  AND token = 'VZ5cKfTJgg4WVY29Pxkim5jFAGKZPkLfX3dJ1Z6AliU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}